# Copyright 2018 AT&T Intellectual Property.  All other rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import testtools

from deckhand.engine import cache
from deckhand import factories
from deckhand.tests.unit import base as test_base


class RenderedDocumentsCacheTest(test_base.DeckhandTestCase):

    def test_lookup_by_revision_id_cache(self):
        """Validate ``lookup_by_revision_id`` caching works.

        Passing in None in lieu of the actual documents proves that:

        * if the payload is in the cache, then no error is thrown since the
          cache is hit so no further processing is performed, where otherwise a
          method would be called on `None`
        * if the payload is not in the cache, then following logic above,
          method is called on `None`, raising AttributeError
        """

        document_factory = factories.DocumentFactory(1, [1])
        documents = document_factory.gen_test({})

        # Validate that caching the ref returns expected payload.
        rendered_documents = cache.lookup_by_revision_id(1, documents)
        self.assertIsInstance(rendered_documents, list)

        # Validate that the cache actually works.
        next_rendered_documents = cache.lookup_by_revision_id(1, None)
        self.assertEqual(rendered_documents, next_rendered_documents)

        # No documents passed in and revision ID 2 isn't cached - so expect
        # this to blow up.
        with testtools.ExpectedException(AttributeError):
            cache.lookup_by_revision_id(2, None)

        # Invalidate the cache and ensure the original data isn't there.
        cache.invalidate()

        # The cache won't be hit this time - expect AttributeError.
        with testtools.ExpectedException(AttributeError):
            cache.lookup_by_revision_id(1, None)